Researchers from the University of California, San Diego (UCSD) and Stanford University found that girls who binge-drink – defined as having four or more drinks for women and five or more for men – showed less activity in several brain regions than teetotal teenagers, both girls and boys, the study said.
"These differences in brain activity were linked to worse performance on other measures of attention and working memory ability," Stanford University psychiatry professor Susan Tapert, a co-author of the study, said.
"This suggests that female teens may be particularly vulnerable to the negative effects of heavy alcohol use," Tapert said.
Why alcohol hits girls harder
Alcohol could affect teen girls' brains more than it does their male counterparts for a number of reasons, including that girls' brains develop one to two years earlier than those of males', said Tapert.
"So alcohol use during a different developmental stage - despite the same age - could account for the gender differences," she said.
Other reasons include hormonal differences between girls and boys, and girls' slower rates of metabolism, higher body fat ratios, and lower body weight.
The findings are "similar to what generally has been found in adult alcoholics: while both men and women are adversely affected, women are often more vulnerable than men to deleterious effects on the brain", Tapert said.
Ninety-five teens took part in the study, including 40 who said they had binge-drunk.
None of the teens who took part in the study had a drink problem. The ones who had binge-drunk did so at a social gathering, but then did not drink again for weeks.
Effects of drinking long-lasting
And yet, warned Edith Sullivan, a professor in the department of psychiatry and behavioural sciences at Stanford University School of Medicine, the negative effects of excessive drinking lingered long after the buzz from the booze was gone.
"Long after a young person – middle school to college – enjoys recovery from a hang-over, this study shows that risk to cognitive and brain functions endures," Sullivan said.
The study, which will be published in "Alcoholism: Clinical and Experimental Research" and is already available says that nearly three in 10 American teens in their final year of high school reported binge drinking in the past month.
(Sapa, July 2011)